Davidson Day School’s Ground Penetrating Research

Mat Saunders, Upper School Faculty & AFAR Director
Since 2014, the AFAR Program at Davidson Day has had the very special opportunity to conduct archaeological research at the medieval castle of Zorita de los Canes in central Spain. This impressive but seldom-noted fortress served as the backdrop for many important moments in Spain’s rich history. The castle began as a Moorish fortress more than 1200 years ago but, apart from its walls, almost all of the construction dates between the 12th and 16th centuries. 
Throughout the following four centuries, control of the castle changed hands between the Moors and the Christian kings of Spain and architectural evidence shows that there were added stylistic elements and expansions with each change of possession. Among Zorita castle's most famous occupants was the Calatrava Order of Knights (one of Spain’s three main orders). In fact, historical records show that it served as the headquarters of the order between 1195 AD and 1212 AD.  

The AFAR Program at Davidson Day was the first archaeological team to carry out long-term systematic research of the castle and over the last nine years, we have made many significant discoveries that have supplied scholars with the majority of what is known of the castle today. Over 120 Davidson Day alumni have worked at this site, and 21 current Davidson Day students will work at Zorita Castle during our 2023 summer program.

Although we have carried out years of research and uncovered a large portion of the castle, time and resources have limited the scope of our work. In fact, we have only excavated around 5% of the area within the castle walls! Fate smiled upon our project last week when a team of scientists from the Universidad Politecnica de Valencia agreed to do a full ground penetrating radar (GPR) survey of the castle. You are probably asking yourself, “what is ground-penetrating radar?” Ground-penetrating radar, commonly referred to as GPR, is an instrument that looks like a lawn mower but instead of chopping blades of grass, it transmits electromagnetic waves into the ground and receives the echos from those waves to measure the variation in the ground below the surface. Essentially, it allows us to see things like walls, subterranean rooms, burials, and other anomalies that lie beneath the ground without lifting a shovel. For archaeologists, this is a valuable tool and one that we rarely have access to due to its expense. 

Last week, I traveled to central Spain to join site directors Dr. Dionisio Urbana and Catalina Urquijo and the GPR team consisting of Dr. Jorge Padin Devesa and Dr. Sergio Navarro Martínez, both professors in the Department of Cartographic Engineering, Geodesy and Photogrammetry at the Universidad Politecnica de Valencia. Davidson Day parents Kyle Lambeth and Dave Hamme also traveled to Spain as volunteers for the GPR survey. Although the final results of the survey will not be available for a number of weeks, the GPR team shared a number of unique anomalies in their initial readouts that lead us to believe that more subterranean rooms below the surface could exist.

These results are all very exciting and will ultimately steer the research plan for our research teams for years to come. We will share the full GPR survey results once they are made available to us.

Author: Mat Saunders, Davidson Day’s international programs director and Zorita de los Canes Archaeological Testing Project director